Blender python array modifier transforms
Using modifier array, e.g.:

def array(self, obj):
    mod = bpy.data.objects[obj.name].modifiers.new(name='array', type='ARRAY')
    mod.count = 10
    mod.relative_offset_displace[0] = 2.5


position and rotation can be calculated from the formula, e.g. 5th element in array would have x = 5 * mod.relative_offset_displace[0], so if original is [0,0,0] then 5th will be [6.25,0,0].